Concrete-mixing apparatus



Nov. 1, 1938. B. F. DEVINE ET AL 2,135,439

CONCREEPE MIXING APPARATUS Filed Sept. 4, 19 36 2 Sheets-Sheet 1 o o V W.

C] l0 I f 5 7 gwumvkwa 7 l ,Bernardlf'flevine,

' 7 I an Charles Eflall,

NOV. 1, 1938;. NE 'A I 2,135,439

CONCRETE MIXING APPARATUS I Filed Sept. 4, 1936 I 2 Sheets-Shea 2 .37 3 III-3J5 BernardF Devine, a Chafles 1 15a,

40 coating of the aggregates.

Patented Nov. 1," 1938 N ED STAT-Es PATENT OFFICE CONCRETE-NIIXING APPARATUS Bernard F. Devine, Milwaukee, and Charles F. Ball, Wauwatosa, .Wis., assignors to Chain Belt Company, Milwaukee, Wis., a corporation of 7 Wisconsin Application September 4, 1936, Serial No. 99,492

12 Claims. (Cl. 259 -177) "Thisinvention relates to apparatus for mixing and/or agitating concrete, and more specifically to apparatus for automatically controlling or varying the mixing speed. In order that the 5 precisenature of the invention may be better understood, it may be saidthat itis well known jto those" skilled in the art that one factor in v the securing of maximum strength in concrete 'isfthe mixing of the raw materials for a time sufficient tocause eachindividual piece of ag- ",gregate, both large and small, to be completely coatedw'ith the binder-in the case of Portland cement concrete, the cement-and-water paste. To this end, concrete specifications usually re- 7715 quire a definite minimum mixing period; and to insure'that the operator. observes this requirementitis common practice to provide concrete J m'i'xih'g machines with automatic timers, or 'fbatchmterdwhich may be either manually or automatically set into operation at the proper time, run for the predetermined mixing period,

or number of drum revolutions, and then give a visualand/or audible signal'to indicate that the batchis completely mixed and maybe discharged.

In most instances, the discharge mechanism'is docked during this mixing period bythe batchmeter, or by automaticcontrol mechanism operating' in conjunction with it, so thatthe batch cannot be prematurely discharged; and in some casesjthe said discharge -mechanism is not only 45f wasteful of power or fuel, with consequent increased cost, and, as has been recently deter- ,mined, may actually. adversely affect the quality and'.strength of theconcrete if continued for considerable time, say more than 45 minutes at 50 accepted mixing speed in agitation be stopped completely at the end of the mixing period, the ".mixture -p articularly in the case of the wetter Ymixes -will tend to segregate, with consequent ill, effect upon the strength when finally placed;

and further, because of the chemical reactions taking place between the water and the cement, it will start to harden or set. On the other hand, f-uel orpower can be saved, segregation can be prevented, and setting can be avoided, if the agitation-be continued at a comparatively slow .5

rate; and the time for discharging the mixture may be delayed for at least an hour, and in many cases for longer periods, without appreciable efiect on the setting or strength qualities of the concrete. 1-0

It is one of the principal objects of the present invention to provide a mixing apparatus for concrete and the like, in which the rate of agitation may be automatically changed, at the conclusion of the predetermined minimum mixing period."l5

It is a further object of the invention to provide a mixing apparatus for concrete and the like, in which the initial mixing may take place for the predetermined minimum mixing period at a relatively rapid rate, at the end of which period the rate will be automatically reduced and the agitation may continue at such lowered rate until discharge, with consequent saving in fuel or power, reduction in costs, and maintainance of the best physical properties in the concrete through pre- 25 ,ventionofsegregation, setting, and over-mixing deterioration.

It is a still further object of the invention to provide amixing apparatus for concrete and the like, in which a batchmeter or timer is 30 adaptedto control'a speed changing or regulating instrumentality which in turn determines the rate of agitation, the parts being so arranged that the batchmeterwillpermit mixing at a relatively rapid rate during the time period or numberof drum revolutions for which the batchmeter is set, and at the conclusion of such period the said batchmeter will cause the speed controlling device to automatically reduce the rate of agitation. The mechanism also preferably makes pro-, 40 Vision for subsequent manual actuation of the sped control instrumentality, so that the speed may be again increased for discharge of the mixture. With the above and other objects in view,

whichwill appear as the description proceeds, the

invention consists in the novel details of con-- struction, and in the novel combinations and arrangements of parts, more fully hereinafter disclosed, and particularly pointed out in the ap-. pended claims. While as will be readily appreciated, the invention is susceptible of use with all types of mixers or agitators, including stationary and paving mixers, it has special application to mixers of the truck or transit type, and for purposes of the present disclosure it has been illus trated and will be described in connection with a well known form of such truck or transit mixer.

Referring to the accompanying drawings forming a part of this specification in which like reference characters designate like parts in all the 'views:-

Figure 1 is a side elevational View of the mixing or agitating unit of a well known form of truck mixer, showing one embodiment of the 7 present invention applied thereto;

Fig. 2 is an enlarged side elevational View, partly broken away, of the essential instrumentalities shown in Fig. 1;.

Fig.3 is a transverse sectional elevational view,

taken approximately on the plane indicated by the line 33 of Fig. 2, looking in the direction of the arrows; and

Fig. lis an enlarged fragmentary elevational view, partly in section, of the operating ccnnec= tions between the batch timer and the speed control instrumentality. I I 1 Referring more particularly to the said drawings, the mixer or agitator unit 55 illustrated therein is of the independent motor driven type and comprises'the mixing receptacle or drum .6

mounted for rotation in, a suitable framework 1 and adapted to be driven by the motor 8 through the drive shaft 9 and suitable gearing contained in the housings I0 and II respectively. The said .motor 8 is usually, although not necessarily,'of

the internal combustion type, in which event it; has associated with it the carburetor or fuel mixing device l2 having the usual throttle valve controlled by the arm or lever l3, whereby the speed of the engine may be regulated in the well known manner,'which in turn will control the speed of rotation of the mixing drum 6.

A timing device or batchmeter mounted-upon suitable supports l6.

' I5; may be One form of batchmeter which is particularly adapted for use in connection with the present invention is illustrated and described in the prior U. S. PatentNo.

2,018,964, granted October 29, 1935, upon an application filed by Rudolph F. Lindow, and such a batchmeter has been illustrated here moreor less diagrammatically. It has a driving shaft l1 extending through its casing by means of which power may be supplied to the timing mechanism in any suitable manner. In the present instance, as is best shown in Fig. 2, said shaft I1 is provided with a worm wheel I8 enclosed within a housing 19 and meshed with a worm 2D which is driven by means of a sprocket 2!,

sprocket chain 22 and sprocket 23, the latter being mounted upon the driving shaft 9 of .the

'mixer unit. The batchmeter I5 may be further provided with a bell or other audible signal device 25, and it also has an arm or lever 26 which is automatically moved back and forth between the full and broken line positions shown in Fig 4 at the beginning and at the end of a timing cycle. That is to say, at the beginning of the mixing period the arm or lever 26 is moved from which aotuates the throttle valve, or other speed regulating device of the motor 8, such connecthe speed of motor 8 and drunrii."v During the.

latter part ofthis'movement, the pin'or roller 40 tions in the present instance being shown in Figs. 3 and 4' as comprising a link 30, one end of which is connected as at 3| to batchmeter lever 25, and

. the other end of which is hooked as at 32, for engagement with a. pin 'or roller 33 carried by a manually operable throttle actuating lever 34, pivotally mounted as at 3.5 on a bracket '36. One end of a rod 31 is connected as at38' to the lever, 34, the other end of said rod beingconnected to throttle lever l3. The manual throttle actuating lever 34 also carries a pin or roller 40, which,

in the fast positionof the lever, is disengaged from'the link 30, as shown in full lines in Fig.

l, but which, as lever 34'is moved to slow position, contacts with the surface 4| of the hook portion. 32, and raises the link, 30 to disengage its hook 32 from the pin or roller 33, as indicated inbroken lines in said Fig. 4.

With the parts and instrumentalities arranged as just described, and assuming them to be in the broken line positions illustrated in Fig. 4 just prior to the initiation of 'a mixing operation, the

throttle actuating lever 34 is manuallymoved to.

its full line position, thus speeding up. the motor 8 and .drum 6, and the batchmeter I5 is set into 2 operation, moving its" lever 26 and link 30 to their:

full line positions, and engaging hook 32 with pin'or roller 33. When 'the'predetermined mixing time has elapsed, or the drumt'h'as made the desired number of revolutions, .th'ebatchmeter will'automatically return. its lever. 23 to the broken lineposition, and through link' 30, hook 32, and pin 33, will return thelever 34 to its broken line slow position, thuscutting down will contact the surface 4! of link 30' and'raise' the linksomewhat, so that at thefconclusion of. the movement the hook. 32 will" be disengaged from pin 33. This is to permit the lever 34 to be interference from the ,link3fi or batchmeter, when it comes time to discharge the mixture.

. :40, 7 again manuallymoved to fast pos1t1on without 7 also permits lever 34 to be moved to fast position before the batchmeter is "started at the beginning of a a mixing operation. On the other hand, if thebatchmeter be started while the lever j 34 is in slow position, surface 41 of link 3ll will merely ride on pin or roller 40 untilhookj'32 is in position to drop behind pin 33 should lever" 34 be moved to fastflposition. f In order thatthe'batchmeten'control may. be rendered wholly inoperative if desired, a cam or eccentric 45 is preferably mounted on an extension 46 of bracket 36, and when moved from.

its full line to its broken line position shown in Fig. 4, will maintainlink3fl in its raised broken line position, so that leve'r34 may be freely ma- V nipulated without interference from the link.

While the mixing unit here illustrated is of the independent motor driventype', it will be immediately obvious that the'invention can be-as well applied to that type of truck mixer in which the power for rotating the drum 6 is derived'through a power take off from the truck traction drive, in I which event the linkage 3l will extend to a suitable change speed gearing interposed in the drum drive and independent of'the traction gear box.

Therefore while one form of the invention'has been illustrated and described, it is obvious that those skilled in the art may vary the precise details of construction and arrangement of the.

parts without departing fromthe spirit of the invention,.and it is not wished to be 'limitedto the above disclosure except as maybeirequired by the claims.

1; In' -apparatu x'ingconcreteand 'the likey a receptacle; means for inducing agitation zaofmaterials in saidreceptacle at apredetermined uniform rate; means for determining the 'd-urationof amixingperiod at said rate; and connectionsbetween said Zfirsti'and second named means whereby the latter will cause the former to induce agitation at a lower uniform rate after the conclusion of said mixing operation. I 2. In apparatus for mixing concrete and-the like, a rotatable receptacle; means. including a I speed regulating instrumentality for rotating said I receptacle to induce agitation of materials therein;means for determining the duration of a mixing operation; and connections between said speed regulating instrumentality and said last named means whereby the latter will control the former ,to cause rotation of said receptacle at a certain uniform rate during said mixing operation, andat a different rate uniform thereafter.

3.'In apparatus for mixing concrete and the like, a rotatable receptacle; means including a Y ing operation;

7 like, a mixing receptacle; a prime mover having a speed regulating device for controllingit; driving" connections between said prime mover and Y receptacle; a batchmeter for determining the duration of a mixing operation,,having a member movable at the conclusion of such operation; and

connections between said batchmeter member and speed regulating device, whereby the former may cause the latter to reduce the speed of the receptacle subsequent to the mixing operation to a uni-' form lower rate and maintain such rate indefinitely.

5. In apparatus for mixing concrete and the like, a rotatable mixing receptacle; a prime mover having a speed regulating device for controlling it; driving connections between said prime mover and receptacle; a batchmeter for determining the duration of a mixingoperation, having a member movable at the'beginning and at the conclusion of such operation; and connections between said batchmeter member and. speed regulating device, whereby the former may control the latter to provide for said prime mover driv- I ing said receptacle at one uniform rate of speed during the mixing operation, and at a different suniform rate of speed subsequent thereto said latter uniform rate of speed being maintained indefinitely.

6. In apparatus for mixing concrete and the like, a rotatable mixing receptacle; a prime mover having a speed regulating device associated therewith for controlling it; driving connections be tween said prime mover and receptacle; a batch-s meter for determining the duration of a period of mixing, having a member movable at the beginning and' at the conclusion of such period; and connections between said batchmeter memher and speed regulating device, whereby the former may control the latter to cause a reduction in the rate of agitation at the conclusion of said mixing operation to a uniform value which'may, be maintained indefinitely.

7 In fapparatus-for mixing concrete and the *said timing 'means arranged to cause said speed varying means to induce mixing at one uniform rate of spee'd duringsaid timed mixing period and at another uniform rate of speed subsequent thereto and to maintain said latter uniform rate indefinitely.

8. In apparatus for mixing concrete and the like, a mixing receptacle; means for inducing agitation of materials in said receptacle; means for controlling the rate of speed of said agitation, manually movable from high to low speed position and vice versa; means for determining the duration of a mixing operation; and connections between said last named means and said manually movable means arranged, should the latter be in high speedposition at the termination of said determined mixing operation, to automatically move it to low speed position.

9. In apparatus for mixing concrete and the like, a mixing receptacle; means for inducing agitation of materials in said receptacle; means for controlling the rate of speed of said agitation, including a lever manually movable from high to low speed position and vice versa; a batchmeter for determining the duration of a mixing operation; and lost motion connections between said batchmeter and lever arranged, should the latter be in high speed position at the termination of said determined mixing operation, to automatically move it to low speed position.

10. In apparatus for mixing concrete and the like, a mixing receptacle; means for inducing agitation of materials in said receptacle; means for controlling the rate of speed of said agitation, including a lever manually movable from high to low speed position and vice versa; a batchmeter for determining the duration of a mixing operation; lost motion connections between said batchmeter and lever arranged, should the latter be in high speed position at the termination of said determined mixing operation, to automatically move it to low speed position; and means arranged to temporarily disengage said connections as said lever reaches low speed position to provide for manual movement thereof to high speed position free from batchmeter control.

11. In apparatus for mixing concrete and the like, a mixing receptacle; means for inducing agitation of materials in said receptacle; means for controlling the rate of speed of said agitation, including a lever manually movable from high to low speed position and vice versa; a batchmeter for determining the duration of a mixing operation; lost motion connections between said batchmeter and lever arranged, should the latter be in high speed position at the termination of said determined mixing operation, to automatically move it to low speed position; and means arranged to temporarily disengage said connections as said lever reaches low speed position to provide for manual movement thereof to high speed position free from batchmeter control, said means being also arranged to provide for automatic re-engagement of said connections when the batchmeter is again started.

12. In apparatus for mixing concrete and the like, a mixing receptacle; means for inducing agitation of materials in said receptacle; means for controlling the rate of speed of said agitation,

tion and vice versa; means for determining the duration of a mixing operation; .conn'ections between said last named means and said manu-' ally movable means arranged, should the latter be in high speed position at the termination of said determined mixing operation, to automati- V cally move it to low speed position; and means wholly free from .means.

" manually movable from high toiow speed posiarranged to disengage and maintainsaideOnnec I tions ineffective indefinitelmto provide for mane- 11a] operation of said speed controlling means control by said determining- BE' 'NA'RD CHARLES 

